In a refinery, tank farm or other industrial setting where personnel must enter a vessel to inspect, repair or maintain the vessel any energy source or inlet capable of allowing energy to enter into the vessel is blinded. To prevent dangerous energy or other substances from entering the vessel a blind, usually a flat pancake like piece is inserted between a set of flanges that have been loosened. This blind blocks any flow through the pipe and allows personnel to enter a vessel without risk of harm.
Blinding does increase a risk of leakage and is extremely time consuming. The operator must remove the bolts around a flange to allow the blind to be inserted. The operator must then remove the blind and reattach the bolts to the flanges. Removing bolts and loosening flanges can produce leaks where none were present before. Further, given that most vessels often have dozens of entry points, the blinding process can be very time consuming. A number of the entry points on a vessel are often non-energy sources. These can be sight glasses or other unused ports that are not connected to any sort of energy source. Non-energy sources are often an open valve or pipe without the desired flanges capable of accepting a traditional blind. There is a desire to blind these non-energy sources to prevent an operator from accidently attaching an energy source while the vessel is being maintained. There is also a need in the industry to reduce the time and cost associated with blinding non-energy sources.
Exposure of energy to personnel could cause serious harm or even death. Therefore, there exists a need to prevent exposure to any energy source while inside a vessel.